Insecticides: Making the Most of Limited Chemistries

While no widespread, plague-like insect infestations hit growers in 2017, a number of traited Bt crops continued to struggle under heavy pest pressure — and growers found some soybean aphids are slipping through go-to controls, writes Lisa Heacox on CropLife.com.

New active ingredients are few and far between, so insecticide manufacturers are getting creative. Here, CropLife® takes a brief look at problems in fields and new strategies for combatting them in 2018.

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Corn Problem Spots

In Indiana, Dr. John Obermeyer, Extension Specialist with Purdue, says Western bean cutworm made a strong appearance in northern counties. Once growers and pest managers realized the problem, many tried aerial foliar insecticides, but most were too late because the worms had reached ears.

The cutworm was first seen in the state in 2006, with first actual damage noted three years later. At one point, researchers actually thought the pest was disappearing, thanks in part to control from the Cry1F Bt trait in corn hybrids.

“It’s come back with a vengeance,” says Obermeyer. “In northern Indiana in 2016, a few growers and researchers noticed that the trait was starting to falter — then in 2017 it really hit the fan. It’s the old typical textbook scenario where over-reliance on any one given control mechanism, whether a pesticide or trait, falters.”